A High Sensitivity Electrochemical Immunosensor Based on Monoclonal Antibody Coupled Flower-Shaped Nano-ZnO for Detection of Tenuazonic Acid

In this paper, an electrochemical biosensor was established for the high-sensitivity detection of Tenuazonic acid (TeA) in fruits based on the enrichment of flower-shaped nano-ZnO and the specific recognition of immune response. Herein flower-shaped nano-ZnO (ZnO NFs) with a hexagonal wurtzite structure and diameter of 700–800 nm were demonstrated to have the optimal specific surface area and outstanding conductivity, compared with different morphology, sizes, and crystal structures of nano-ZnO. Second, the ZnO NFs were used as carriers for efficiently immobilizing monoclonal antibodies to obtain antibody bioconjugates, which were anchored on the 2-mercaptobenzoic acid-modified gold electrode by amide reaction. In the presence of TeA, the monoclonal antibody could specifically recognize and bind to it, resulting in a decrease in electron transfer ability on the gold electrode surface. Finally, the electrochemical biosensor showed a range from 5 × 10−5 μg/mL to 5 × 10−1 μg/mL with a detection limit of 1.14 × 10−5 μg/mL. Furthermore, it exhibited high selectivity for TeA among other analogs, such as Altenuene (ALT) and Alternariol (AOH). Notably, the proposed strategy could be employed to monitor TeA in tomato and citrus, showing potential application prospects in practical application and commercial value.